HDMI port doesn't work after the use of VGA

Hey,
strange title, I know.
I was using the HDMI port of my Laptop to connect it to my TV and the VGA port to connect an additional monitor to my Laptop.
So the usual screen I had was my Laptop's plus the additional monitor and in case I wanted to watch a movie I used Windows+P and the option ;projector only(hope the translation is correct) to get the screen of my main monitor to my TV.
This worked just fine till I connected a beamer via the VGA port to my Laptop.
Now my Laptop doesn't use the HDMI port a the ;projector; port, instead it uses the VGA port.
It doesn't even recognize it when I have nothing plugged into the VGA port.
I installed the newest graphic drivers, I plugged in nothing but the HDMI cable(with my TV), nothing seems to work.
It won't use the HDMI port anymore.
I really want to watch movies again with my TV, so I hope you guys have an idea what I could do

I'm using Windows 7 64bit with an ATI Mobility Radeon HD 4650.

Thanks in advance
oLmm